Introduction to Tandem X.25 Capabilities

Data-Link-Layer Components
What is X.25?
065307 Tandem Computers Incorporated 1–25
Figure 1-17. LAPB Station Configuration
Primary
Substation
Secondary
Substation
Primary
Substation
Secondary
Substation
013
(For Command and
I-Frame from DTE)
Address B (01)
(For Command and I-Frame
from DCE)
Address A (03)
(For Response from
DCE)
(For Response Frames
from DTE)
DTE
DCE
Address B (01)
Address A (03)